This invention relates to oil removal and more particularly to oil spill clean-up using magnetizable particles.
Oil spills can have devastating environmental consequences and many technologies exist to mitigate the effects. Rapid and innovative approaches are still needed, however, for successful remediation of major oil spills such as from the Macondo well in the Gulf of Mexico in 2010. Kaiser, in U.S. Pat. No. 3,635,819, has proposed mixing a colloidally stabilized magnetic fluid with spilled oil to form a stable suspension. The oil is then collected by application of a magnetic field to the oil/magnetic fluid combination. The practice of Kaiser's approach requires the use of ferrofluids containing single magnetic domain nanometer-sized particles with a stabilizing surfactant or surface coating to prevent magnetic particle agglomeration. The '819 patent limits the particles to a size less than 300 Å which is 30 nm. Such small particles are necessary for long-lived ferrofluids. These particles have a single magnetic domain and a net magnetic moment. These nanometer-sized particles necessarily have small surface areas which limit their ability to collect oil on their surfaces. Kaiser in claims 4 and 5 requires that the ferrofluid is sprayed over the surface of the oil spill and the ferrofluid should have a density less than the sea water on which it floats. This patent allows for the containment of the spilled oil, removing the density limitation when using a ferrofluid, and by magnetizing either the oil or water using alternate methods.